U of A physicists develop new technique to create quantum memory

Discovery offers a simpler way to build a crucial element for more secure data communication and storage.

Physicists at the University of Alberta have developed a new way to build quantum memory that could help pave the way for a next-generation quantum internet that is more secure but can still take advantage of existing network technology like fibre-optic cables.

"We've developed a new way to store pulses of light-down to the single-photon level-in clouds of ultracold rubidium atoms, and to later retrieve them on demand by shining a 'control' pulse of light," said Lindsay LeBlanc, assistant professor of physics and Canada Research Chair in Ultracold Gases for Quantum Simulation. LeBlanc conducted the research with post-doctoral fellow Erhan Saglamyurek.

Quantum memory is an important component of quantum networks, serving much the same role as hard drives in today's computers.

The new method developed by LeBlanc and Saglamyurek, which is best suited for applications requiring high-speed operations, also has considerably fewer technical requirements than common quantum storage techniques.

"The amount of power needed is significantly lower than current options, and these reduced requirements make it easier to implement in other labs," said Saglamyurek.

The discovery will allow for the crucial scaling up of quantum technologies, which has proven the biggest challenge to date in the emerging field. For example, Leblanc noted, because it can store data until it is needed, the new memory could be useful for transmitting data securely over longer distances.

The research team also included two graduate students working in LeBlanc's lab, Taras Hrushevskyi and Anindya Rastogi, and Khabat Heshami from the National Research Council in Ottawa.

The study, "Coherent Storage and Manipulation of Broadband Photons Via Dynamically Controlled Autler-Townes Splitting," was published in Nature Photonics.